WO 2011/080103, WO 2012/062803, WO 2012/062804, WO 2012/140117, WO 2013/037690, WO 2013/167455, and WO 2013/167454 disclose various double-acylated GLP-1 derivatives, and U.S. Pat. No. 7,291,594 B2 discloses various GLP-1 peptide analogues including some that have Lys residues at positions 36 and 37.